Compound Interest Calculator Definition
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Use these tools to compute values based on this definition.
Further Reading
Deep dive into the math and concepts with our comprehensive guides.
What is Compound Interest? Guide to Compounding Growth
Compound interest is the interest you earn on both your original money and on the interest you keep accumulating. It is the core concept behind long-term wealth building.
Simple vs Compound Interest: What is the Difference?
A detailed breakdown of simple versus compound interest. Learn the math behind each and understand how compounding frequency affects your money.
Core Glossary Term
Read the formal mathematical definition.
Worked Examples
Step-by-step calculations showing how to apply this concept.
Investing $500 a Month for 30 Years
This example demonstrates the power of compound interest over a long time horizon. Even though the investor only put in $180,000 of their own money, the balance grew to over $600,000 because the interest earned kept generating its own interest.
View in Calculator →Frequently Asked Questions
What inputs are needed for a compound interest calculator?
You typically need the initial principal, the interest rate, the compounding frequency, the time horizon in years, and any regular contributions.
Does compound interest apply to debt?
Yes. While it helps investments grow, it also causes debt (like credit card balances) to grow exponentially if not paid off.